In diesel electric or electric locomotives, an electric traction motor armature or drive shaft having a pinion gear on one end thereof is coupled to a bull gear on a locomotive axle to drive a set of wheels. The gears are enclosed within a gear case comprised of a pair of matable sections which provide an enclosure for the retention of lubricant such as illustrated in U.S. Pat. Nos. 4,347,759 and 4,470,324.
While the concepts disclosed in the above noted patents have been instrumental in making a significant improvement in the retention of lubricant in traction motor gear cases, such patents dealt primarily with the reduction of lubricant losses through the axle and bull gear access openings into the gear case.
The present invention relates to another access area into the gear case, namely the armature shaft bearing assembly. The latter is unique since it is not only desirable to keep the heavy asphaltic lubricant used to lubricate the pinion and bull gears in the gear case, but also to keep the asphaltic lubricant from migrating to the traction motor armature shaft bearings where it can dilute and contaminate the armature bearing grease thereby resulting in failure of the armature bearing itself.
However, up to this point it has been difficult to keep the gear lubricant from migrating into the armature bearing assembly because of the high lubricant splash pressures generated by the large bull gear carried by the locomotive axle.
Failure to keep the gear case lubricants from migrating into the armature bearing mounting assembly can result in numerous severe problems such as failed armature bearings because of armature bearing grease dilution, high gear tooth wear because of low lubricant levels in the gear case, and of course locomotive "down-time" because of the need to replenish gear case lubricants.